Development of the dairy products incorporated with co-product bioactive compounds-rich as an alternative ingredient in the food industry.

The objective was to optimize the phenolic compounds extraction from cocoa shells using the simplex-centroid design with a mixture of solvents (water, methanol, and acetone) as its components, to prove the presence of these compounds and antioxidant activity. Also, the development of dairy products, such as milk beverages and dairy desserts, with bioactive compounds, through the replacement of cocoa powder by cocoa shell was studied and evaluated sensorially. The extraction optimization indicated that a solvent with 56.44% water, 23.77% methanol, and 19.80% acetone are ideal for maximizing the phenolic compounds. In addition, the cocoa shell showed a high antioxidant activity by the methods ß-carotene/linoleic acid, FRAP, and phosphomolybdenum complex. The Check-All-That-Apply, Cochran's Q test, contingency analysis, and hierarchical cluster analysis allowed description characteristics of the dairy products and showed sensory differences between formulations with 100% cocoa shell and others. Both dairy products had good sensory acceptance in all attributes evaluated (appearance, flavor, texture, and overall impression), and their scores did not differ statistically by Tukey's test (p > 0.05). Thus, the cocoa shell is shown as an alternative substitute ingredient to be used in the dairy industry.

Physiological changes in green and red cherry tomatoes after photocatalytic ethylene degradation using continuous air flux.

In this work photocatalytic ethylene degradation (TiO2-UV) was applied in green cherry tomatoes with the aim to control biochemical and physiological changes during ripening. Photocatalytic process was performed at 18 °C ± 2 °C and 85% HR for 10 days using continuous air flux. Ethylene, O2 and CO2 concentration from cherry tomatoes under TiO2-UV and control (c) fruits, were measured by GC-MS for 10 days. After that, the tomatoes were stored for 20 days. During the photocatalysis process, ethylene was completely degraded and control fruits, the ethylene was 28.73 nL/g. Respiration rate was lower for fruits under TiO2-UV than control. During storage period, cherry tomatoes treated by TiO2-UV, showed lower ethylene concentration, respiration rate, total soluble solid, lycopene, sugar and organic acid content than control showing that the fruits treated with photocatalysis did not reach the full maturity. In addition, all the cherry tomatoes showed different maturity stages. Fungal incidence was higher in control fruits than fruits treated with photocatalysis. This research showed for the first time that photocatalytic technology preserved the physiological quality of cherry tomatoes for 30 days of storage, being a promised technology to preserve cherries tomatoes.

A review on TiO2-based photocatalytic systems applied in fruit postharvest: Set-ups and perspectives.

Titanium dioxide (TiO2) is a photocatalytic material used to degrade ethylene, and it has been studied as an alternative postharvest technology. Although several studies have indicated the effective action of TiO2 photocatalysis for delaying the fruit ripening, photocatalytic systems need to be well-designed for this application. Fruit is susceptible to environmental conditions like temperature, relative humidity, atmosphere composition and exposure to UV-light. This fragility associated with its variable ethylene production rate over its maturation stage limits the photocatalysis parameters optimization. Thus, this review aims to detail the reaction mechanisms, set-up, advantages, and limitations of TiO2 photocatalytic systems based on polymers-TiO2 nanocomposites and reactors containing TiO2 immobilized into inorganic supports designed for fruit applications. It is expected that this review can elucidate the fundamental aspects that should be considered for the use of these systems.

Hydroxypropyl methylcellulose-TiO2 and gelatin-TiO2 nanocomposite films: Physicochemical and structural properties.

Photocatalytic properties of titanium dioxide (TiO2) have been widely studied. However, its tendency to aggregation in biopolymer-based nanocomposites limits its application for food packaging and has been few studied. The aim of this work was to study the dispersion of TiO2 (0-2 wt%) incorporated in the hydroxypropyl methylcellulose (HPMC-TiO2) and gelatin (gelatin-TiO2) film forming solutions. Particle size and zeta potential of TiO2 nanoparticles were investigated. Nanocomposite films were characterized as to the thickness, moisture content, solubility, color, absorption to the light, relative opacity, morphology, chemical composition, crystallinity, thermal and mechanical properties and water vapor permeability (WVP). TiO2 nanoparticles showed better dispersion in acid medium than water. Moisture content, water solubility and WVP of the gelatin-TiO2 films were influenced by the incorporation of TiO2, while HPMC-TiO2 films were not. The increase of relative opacity of the films as TiO2 was more attenuated for the gelatin-TiO2 films due to lower TiO2 aggregation in gelatin. Morphology, chemical composition, crystallinity and thermal properties of the films evidenced that TiO2 was better dispersed in both matrices at 1 wt%. It was also concluded that TiO2 aggregation generated more biphasic regions in HPMC than generated in gelatin, which caused a microstructural reorganization in the matrices.

Performance of nanofiltration process during concentration of strawberry juice.

The aim of this study was to evaluate the microfiltration and nanofiltration of strawberry juice. Processes performance was evaluated in terms of resistances-in-series, flux decline modeling and extract quality (maintenance of the phenolic compounds). The results obtained showed that concentration polarization is the main resistance to permeate flux in nanofiltration process, representing around 95% of the total resistance. Microfiltration process suffered more influence of the concentration polarization and fouling, next to 47% for both resistances. For all the processes, Hermia's pore blocking models presented good fitting, with R2 over 0.85. The same behavior was observed for a conjugated model which provided a realistic description (R2 > 0.76). Also, nanofiltration process allowed phenolic compounds maintenance, demonstrating the efficiency of this process for strawberry juice concentration.

Effect of supercritical carbon dioxide processing on Vibrio parahaemolyticus in nutrient broth and in oysters (Crassostrea gigas).

This study aimed to evaluate the technical feasibility of supercritical carbon dioxide (sc-CO2) treatment for Vibrio parahaemolyticus inactivation in oysters (Crassostrea gigas) and in nutrient broth. For this purpose, a variable-volume reactor was used as experimental system and a 23 factorial design was adopted considering the mass ratio between carbon dioxide and the product, pressurization and depressurization rate and pressurization cycles. Through statistical analysis of the experimental data, the mass ratio of 1:0.8 (product:carbon dioxide), depressurization rate of 10.0 MPa/min and one cycle of pressurization was determined as the best process condition to eliminate V. parahaemolyticus, and this was the condition used for the inactivation kinetic analysis. Comparison between the inactivation kinetics of V. parahaemolyticus showed that the behavior of this microorganism inactivation depends on the environment in which it operates and its initial count. The results confirm that the supercritical carbon dioxide is effective in inactivating microorganisms in oysters, including pathogenic V. parahaemolyticus, demonstrating the potential of this technology in the food industry.